The detection and/or differentiation of oligonucleotides and portions of DNA and RNA, respectively, with an electron microscope has caused difficulties so far. Up to the present, there is no satisfactory possibility of visualizing DNA and RNA by electron microscopy in a reproducible manner to carry out studies therewith.
Therefore, it is the object of the present invention to provide a product by which a signal can be attached to the DNA and/or RNA already during the synthesis, if possible, by simply modifying the DNA and/or RNA so as to render the DNA and/or RNA better detectable by means of an electron microscope.
This object is achieved by the features of claims 1, 9, 12 and 14. Advantageous embodiments follow from the dependent claims.